Geothermal systems work by using the ground beneath our feet, which is warmer than the outside air in the winter and cooler in the summer. Inserting a series of pipes into the ground allows heat to be transferred to and from your home. In this process heat is not created, it is transported, therefore no fuel is burned. Geothermal Heat Pump Systems can be separated into two basic components.
- Heat Pump – the inside unit known as the heat pump
- Heat Transfer System.
- Ground Loop – sealed underground pipes which connect to the heat pump using a pump to transfer fluid through the loop and to heat pump
- Open Loop – well water supplied through the heat pump and discharged to another body of water (discharge well or pond).
Winter Operation: The underground pipes, called a ground loop, circulate fluid which absorbs the heat from the earth and returns it to the indoor heat pump. The heat pump extracts the heat from the fluid then distributes it throughout your home as warm air. With the heat removed, the fluid is re-circulated to collect more heat from the ground. In this case, the loop fluid is warmer when it comes into the home than when it goes back into the earth since the heat is being removed.
Summer Operation: The indoor heat pump takes the hot air from your home and removes the heat. This leaves behind cool air to be distributed through your vents as air-conditioning. The removed heat from the air is rejected into the earth through the ground loop. In this case the fluid is warmer leaving the home then when it returns since heat is rejected into it.
A desuperheater comes as a part of geothermal heat pumps. These can be used to provide the entirety of hot water for showers, sinks or whatever else you can think of. Overall energy demand in a building can go down significantly if a part of the hot water is supplied by a geothermal heat pump.
High efficiency rates combined with low operating and maintenance costs resulting in an annual energy savings of between 30% and 60%. Numbers from US Environmental Protection Agency (EPA) show that homeowners save 30-70% on heating and 20-50% on cooling costs by using geothermal heat pumps compared to other conventional systems. This translates to roughly $400 to $1,500 annual savings.